Curable adhesive compositions containing reactive multi-functional acrylate

ABSTRACT

Disclosed are adhesive compositions include polymerizable resin, preferably in an amount of from about 10 wt % to about 90 wt % and multifunctional acrylate, preferably in an amount of from about 5 wt % to about 30 wt %. The polymerizable resin can include free radical initiated vinyl addition resins. The adhesives in preferred embodiments exhibit enhanced bonding strength of the adhesive at high temperatures, such as at about 80° C., and enhanced the fire resistance.

RELATED APPLICATIONS

The present application is a divisional application based on U.S.application Ser. No. 10/679,806 filed Oct. 6, 2003, now U.S. Pat. No.7,544,739, which is related to and claims the priority benefit of U.S.provisional application Nos. 60/425,091 and 60/425,099, each of whichwas filed on Nov. 8, 2002 and all of which are incorporated herein byreference.

TECHNICAL FIELD

The present invention relates to adhesive compositions especially welladapted for use in anchoring materials in or to concrete or masonry, andto methods of anchoring. More particularly, this invention relates tocurable adhesive compositions comprising polymerizable vinyl containingcompound(s) and reactive multi-functional acrylate compound(s), tomethods for bonding using such compositions, and to the bondedstructures produced using such compositions or methods.

BACKGROUND OF THE INVENTION

Many applications require that a material be anchored in or to concreteor masonry. For example, anchor bolts are employed in various fields ofengineering and construction as strengthening or reinforcing members inrock formations, or in concrete or masonry structural bodies. The bolts,which are typically metallic, are inserted into holes in the rockformations, or concrete or masonry structural bodies, and are fixed oranchored therein by means of an anchor composition. Objects that havebeen attached to concrete or masonry using anchor bolts include, but arenot limited to, electrical conduits, panels, piping and wall sections.Adhesive anchors are preferred over mechanical anchors for anchoring insoft concrete or masonry because, among other reasons, adhesive anchorsplace less stress on the concrete or masonry. As used herein, the term“masonry” shall include, but is not limited to, stone, brick, ceramictile, cement tile, hollow concrete block and solid concrete block.

It has been known to use curable synthetic resins as the primaryadhesive for the safe fastening of anchoring rods, bolts and similardevices in solid rock, masonry, concrete and the like. Typically, butnot exclusively, certain of the starting components of the adhesivecomposition are kept separate from one another and then combined at ornear the point of fastening. In such so called two part systems, thecomponents which are kept separate until the time of use are combined atthe site and then introduced to the anchor bolt, the bore or holeprepared to receive the bolt, or both. Thus, the formation of the curedadhesive body that binds the fastener to the base structure is initiatedat about the time the fastener is placed in its final position.

Many of the curable adhesive compositions currently used in theindustry, and in particular the field of anchoring in or to concrete,rock, and like materials, are based on compounds that are polymerized orcured by addition polymerization of monomers, oligomers, prepolymers andlike compounds that have at least one ethylenic unsaturation in themolecule and thus undergo vinyl addition polymerization curing. Forexample, many acrylic and epoxy-based adhesive compositions are cured bythis mechanism this fashion.

Although the curable adhesive compositions, which have heretofore beenused as anchor compositions, have performed with a certain degree ofsuccess, applicants have come to appreciate that dramatic and unexpectedimprovement in performance is not only desirable but also possible.

SUMMARY

Applicants have discovered that the performance of many types ofadhesive compositions, but preferably adhesives cured by vinyl additionpolymerization and even more preferably free radical initiated vinyladdition polymerization, can be dramatically improved by incorporationinto the adhesive formulation a reactive multifunctional acrylate.Applicants have found that the incorporation of reactive multifunctionalacrylate into adhesive compositions enhances the bonding strength of theadhesive, particularly at relatively high temperatures, such as at about80° C., and also in certain embodiments enhances the fire resistance ofthe cured adhesive.

While it is contemplated that the reactive multifunctional acrylate ofthe present invention may be used to best advantage in adhesives basedon free radical-initiated vinyl addition polymerization, it is believedthat use of the reactive multifunctional acrylate may also providesubstantial benefit to adhesives generally, including those adhesiveswhich undergo polycondensation polymerization, acid catalyzed vinyladdition polymerization, base catalyzed vinyl addition polymerization,and combination of two or more of any of these forms of polymerization.

In certain preferred embodiments, the adhesive formulation isacrylic-based, including by way of example the acrylic-based adhesivesdisclosed in U.S. Pat. No. 5,965,635—Rancich et al, which isincorporated herein by reference. In other preferred embodiments theadhesive vinyl ester based, as described in more detail hereinafter.

In general, however, the adhesive compositions of the present inventioninclude from about 10 wt % to about 90 wt % of polymerizable resin andfrom about 5 wt % to about 30 wt %, multifunctional acrylate. As usedherein the term “reactive multifunctional acrylate” refers to compoundsthat have at least two acrylate functionalities that are reactive, underthe conditions used to cure the adhesive, with at least one of thecompounds involved in the curing reaction or formed by the curingreaction. As used herein, the term “acrylate functionality” refers to afunctional group having the general structure illustrated below:

where R may be any group, which does not substantially interfere with orprevent reaction of the multifunctional acrylate compound with thepolymerizable resin. In preferred embodiments, R is independently H or asubstituted or unsubstituted alkyl, aryl, oxyalkyl, arylalkyl, oroxyalkylaryl. In highly preferred embodiments each R is H.

Applicants have found that exceptional results can be achieved inaccordance with the present invention by use of the present reactivemultifunctional acrylate with polymerizable resins comprising, andpreferably consisting essentially of, select polymerizable vinyl estercompounds in combination with a select reactive diluent for thepolymerizable vinyl ester compounds. Furthermore, applicants havediscovered that unexpectedly superior performance is possible when thepolymerizable vinyl ester compounds are present in the adhesivecompositions in amounts of from about 10 wt % to about 30 wt %, and evenmore preferably from about 10 wt % to about 25 wt %, particularly whensuch amounts are used in combination with a substantially styrene-freereactive diluent, preferably vinyl toluene, in a vinyl ester:reactivediluent weight ratio of from about 0.8 to about 3, and even morepreferably from about 0.8 to about 1.5. Furthermore, applicants havefound that unexpectedly superior results are generally achieved when thepolymerizable vinyl ester compounds are present in the adhesivecompositions in amounts of from about 70 pbwa to about 95 pbwa, and evenmore preferably about 85 pbwa to about 95 pbwa, wherein the term “pbwa”means part by weight based on active components, as more particularlydefined hereinafter.

One aspect of the present invention provides an adhesive compositioncomprising polymerizable vinyl ester comprising one or more repeatingunits and at least one terminal vinyl carboxylate, preferably a C₃-C₆vinyl carboxylate, where the ratio of the number of repeating units tothe number of terminal vinyl carboxylate units is, on average in thecomposition, from about 0.4 to about 2.0.

Another aspect of the present invention provides adhesive compositionswhich are especially well adapted for anchoring materials in or toconcrete or masonry, which comprises, in combination with reactivemultifunctional acrylate, a polymerizable vinyl ester corresponding toformula (I) below,

wherein

-   -   Ar is substituted or unsubstituted aryl radical with a valence        of at least two,    -   R is independently a substituted or unsubstituted divalent        radical derived from alkyl, oxyalkyl, arylalkyl, or        oxyalkylaryl,    -   R² is independently H, substituted or unsubstituted vinyl        carboxylate radical, substituted or unsubstituted epoxide ester        radical, or R,    -   for each R_(x), x is independently 0 or 1,    -   for each O_(y), y is independently 0 or 1,    -   for each (O—R²)_(z), z is independently 0 to 4, provided that at        least one y must not be zero if z is zero, and    -   n is from about 1 to about 5.        An important aspect of certain embodiments of this aspect of the        present invention resides in the formulation of the adhesive to        include the polymerizable vinyl ester compounds of formula I        such that the ratio of n to the number of vinyl carboxylate R²        groups is, on average for the composition, from about 0.4 to        about 2.0, more preferably from about 0.4 to about 0.7, and even        more preferably from about 0.4 to about 0.5.

Generally, the compositions of the present invention also include anethylenically unsaturated monomer reactive with the polymerizable vinylester and compatible with the reactive multifunctional acrylate. It issometimes common practice to refer to such a combination ofpolymerizable polymer and reactive diluent as a “resin,” and suchterminology will sometimes be used herein to refer to such combinations.In certain highly preferred aspects of the present invention, thereactive diluent comprises vinyl toluene, and even more preferablycontains no substantial portion of styrene.

In another aspect of the present invention, the present compositioncomprises polymerizable vinyl ester having a glass transitiontemperature (T_(g)) of from about 80° C. to about 130° C., and morepreferably from about 90° C. to about 110° C. The preferred compositionsalso have a heat diffraction temperature (HDT) of from about 90 EC toabout 130 EC, and more preferably from about 100° C. to about 120° C. Incertain preferred embodiments, the vinyl ester has a glass transitiontemperature of about 130 EC and a heat diffraction temperature (HDT) ofabout 130° C.

Optionally but preferably the present compositions also include a curingcatalyst, activator and filler.

An important aspect of the present invention is the provision ofadhesive compositions, which produce excellent bond strength,particularly at relatively high temperatures. In preferred embodiments,the present adhesive compositions achieve pull out performance at onehour at a temperature of about 23° C. of at least about 70 KN, and atabout 24 hour at a temperature of 23° C. of at least about 80 KN, andafter about 24 hours at about 80° C. has a pull out force measured at atemperature of 80° C. of at least about 50, with pull out force beingmeasured as in the examples hereof.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention provides adhesive compositions, and moreparticularly compositions and methods for anchoring materials in or toconcrete or masonry. The materials to be anchored in or to concrete ormasonry include, but are not limited to, metallic objects, such as steelbolts, ceramics, other concrete or masonry objects, plastics, glassesand woods.

The present compositions comprise active components and optionally butpreferably certain inactive components. As used herein, the term “activecomponents” refers to those components, which participate in curing ofthe composition, either directly as a reactant or indirectly as acatalyst, inhibitor or the like.

As mentioned above, one of the important active components of thepresent invention is the reactive multifunctional acrylate. It iscontemplated that numerous compounds are adaptable for use as thereactive multifunctional acrylate of the present invention, and all suchcompounds are useful within the broad scope of the present invention. Inhighly preferred embodiments, the reactive multifunctional acrylate isat least tri-functional, and in certain embodiments at leasttetra-functional, and in certain other embodiments at leastpenta-functional. Of course, the reactive multifunctional acrylate ofthe present invention may comprise a combination of two or moremulti-functional acrylate compounds, with each independently having thesame or different levels of functionality. A preferred tri-functionalacrylate is trimethylolpropane, which is sold under the tradedesignation SR-351 by Sartomer Company of Exton, Pa., USA. A preferredpenta-functional acrylate is dipentaerythritol tetraacrylate, which issold under the trade designation SR-399 by Sartomer Company of Exton,Pa., USA.

Although applicants do not intend to be bound by or to any particulartheory of operation, it is believed that the reactive multifunctionalacrylates of the present invention act to provide numerous and effectivecross-linking sites for the adhesive composition as it cures, thusimproving the density and other physical properties of the curedadhesive, such as pull out strength and fire resistance.

The relative amount of reactive multifunctional acrylate included in thepresent compositions may vary widely depending on numerous factors, suchas for example the functionality of the compound, the other componentsof the composition, and the like. Nevertheless, the preferredembodiments of the present adhesive compositions comprise from about 1weight percent (wt. %) to about 40 wt % of reactive multifunctionalacrylate, more preferably from about 3 wt % to about 30 wt %, and evenmore preferably from about 5 wt % to about 10 wt %. It is also preferredthat the present adhesive compositions comprise from about 5 pbwa toabout 30 pbwa of reactive multifunctional acrylate, more preferably fromabout 10 pbwa to about 30 pbwa, and even more preferably from about 10pbwa to about 25 pbwa. As used herein, the designation “pbwa” meansparts by weight based on the total active components in the adhesivecomposition. Furthermore, unless otherwise specifically indicated to thecontrary, the weight percentages and pbwa of the components in thepresent adhesive compositions as specified herein refer to thecomposition after it has been formulated for use in bonding. Thus, fortwo part compositions of the type described hereinafter, the percentagesand pbwa values refer to the adhesive composition based on thecombination of parts A and B of such compositions.

Further in terms of active components, the present compositions compriseat least one polymerizable compound, preferably in the form of a resin.Although the remainder of this specification will refer to compositionsbased on vinyl ester resins, it will be appreciated by those skilled inthe art that the descriptions contained herein with respect to on vinylester resins can be adapted for use in connection with other types ofresins.

The present compositions comprise at least one polymerizable vinyl estercompound and optionally but preferably a reactive diluent for thepolymerizable vinyl ester compound. Other active components that areincluded in certain preferred embodiments include, but are not limitedto, catalyst (preferably a free-radical catalyst), chain transfer agent,inhibitor (preferably a free-radical inhibitor), activator, promoter,impact modifier, cross linking agent and coupling agent. In terms ofinactive components, it is desirable in certain embodiments to includein the composition filler, non-reactive diluent, thixotropic agent,fragrance, antifoaming agents, wetting agents, and fungicides.

It is contemplated that the relative proportions of the componentsincluded in the present compositions may vary widely depending onnumerous factors, such as for example the contemplated environment ofuse, the desired strength of the bond to be formed, the particularmaterials to be bonded, and other factors. Nevertheless, the preferredaspects of the present adhesive compositions comprise from about 5weight percent (wt. %) to about 50 wt % of polymerizable vinyl estercompound, more preferably from about 10 wt % to about 40 wt %, and evenmore preferably from about 10 wt % to about 30 wt %. It is alsopreferred that the present adhesive compositions comprise from about 20pbwa to about 65 pbwa of polymerizable vinyl ester compound, morepreferably from about 25 pbwa to about 60 pbwa, and even more preferablyfrom about 30 pbwa to about 60 pbwa.

As described above, the present compositions preferably containpolymerizable vinyl ester compound in the form of vinyl ester resin,which includes reactive diluent. Although the relative amounts ofreactive diluent of vinyl ester may vary widely within the scope hereof,it is generally preferred that the vinyl ester resin comprise from about35 wt. % to about 65 wt. %, on the basis of the total weight of theresin, of reactive diluent, with the balance preferably consistingessentially of polymerizable vinyl ester compound. In such embodiments,it is preferred the present adhesive compositions comprise from about 20weight percent (wt. %) to about 70 wt % of vinyl ester resin, morepreferably from about 30 wt % to about 50 wt %, and even more preferablyfrom about 35 wt % to about 45 wt % of said resin. It is also preferredthat the present adhesive compositions comprise from about 70 pbwa toabout 98 pbwa of said resins, more preferably from about 75 pbwa toabout 95 pbwa, and even more preferably from about 85 pbwa to about 95pbwa of such resins.

The composition may be dispensed using various methods known to thoseskilled in the art. For example, the composition may be dispensed usinga dual cartridge device similar to a caulk gun, or the composition maybe dispensed using a glass or film capsule. The composition may also bedispensed in bulk from bulk containers using meter-mix equipment, whichis known to those skilled in the art. U.S. Pat. Nos. 4,651,875,4,706,806 and 4,729,696, the disclosures of each of which areincorporated herein by reference, are directed to the use of glasscapsules to dispense the composition in the form of a two part system.It is recognized that the amounts of the various components of theanchor composition may vary depending on many factors, including on thetype of dispensing system used.

In preferred dispensing methods, the anchor composition is formed by themixing of a first composition (sometimes referred to herein as the “A”part) which contains the resin, and which may contain an inhibitor toprevent premature polymerization, but does not include any substantialamount of curing catalyst and a second composition (sometimes referredto herein as the “B” part) which contains the catalyst and which remainsapart from the A part until the time of use. Typically, mixing of the Apart and the B part occurs immediately before the anchor composition isto be used. For example, when the anchor composition is dispensed usinga dispensing gun, the first composition and the second composition,which are contained in separate cartridges of the dispensing gun, may bemixed as they are ejected from the cartridges and applied to either theconcrete or masonry, the material to be anchored to the concrete ormasonry, or both. Similarly, when the anchor composition is dispensedusing a glass capsule, the capsule is typically comprised of twochambers that contain the first composition and the second composition,respectively. When the glass capsule is crushed, the two chambers arecrushed and the contents are allowed to mix, forming the anchorcomposition. For embodiments in which the anchor composition isdispersed in bulk, the A part and the B part may be stored in separatebulk containers and combined through pumping with mixing in theappropriate ratio to make the anchor composition.

Although the present invention is described above in the form of a twopart composition, it is contemplated that it may be possible toformulate adhesives in accordance with the present invention as aone-part adhesive, and such formulations are within the scope of thepresent invention. For example, it may be possible to formulate thepresent adhesives as in the form of a single component anaerobicadhesive, and such a formulation is within the scope hereof.

It is also generally contemplated that the amount of catalyst used inthe present compositions may vary widely depending on numerous factors,the present adhesive compositions preferably comprise from about 0.5 wt% to about 10 wt % of catalyst, more preferably from about 1 wt % toabout 8 wt %, and even more preferably from about 2 wt % to about 6 wt %catalyst. It is also preferred that the present adhesive compositionscomprise from about 0.5 pbwa to about 25 pbwa of catalyst, morepreferably from about 5 pbwa to about 20 pbwa, and even more preferablyfrom about 5 pbwa to about 15 pbwa of catalyst.

Initiators and activators, if included in adhesive compositions of thepresent invention, as is preferred, are preferably present in amounts ofup to about 0.05 wt % to about 1 wt %, and even more preferably fromabout 0.1 wt % to about 0.5 wt %. It is also preferred that the presentadhesive compositions comprise from about 0.1 pbwa to about 5 pbwa ofinitiator and even more preferably from about 0.1 pbwa to about 1 pbwa.

Promoters are typically used in amounts up to about 0.5% by weight ofthe composition, and preferably about 1 part per million to about 0.5%by weight of the entire composition.

The preferred aspects of the above-noted components other than thereactive multifunctional acrylate, together with the type and amounts ofother additives to the present compositions, are described in detailbelow.

The Polymerizable Vinyl Ester Compound

It is contemplated that known methods for formation of polymerizablevinyl ester compounds and resins can be adapted in view of the teachingscontained herein to form compounds and resins in accordance with thepresent invention, and all such materials are considered to be withinthe scope hereof. In preferred embodiments, the polymerizable vinylester of the present invention is formed by the reaction of an epoxycompound with an ethylenically unsaturated carboxylic acid, anhydride oralcohol, usually with the use of a polymerization inhibitor to preventthe vinyl ester resin from gelling. In view of the teaching containedherein, it is believed that vinyl ester resin in accordance with thepresent invention may be prepared by any of the methods disclosed in anyof the following patents, each of which is incorporated herein byreference: U.S. Pat. No. 3,256,226 to Fekete et al., and U.S. Pat. No.3,317,465 to Doyle et al., both assigned to H. H. Robertson Co.; U.S.Pat. No. 3,345,401 to May; U.S. Pat. No. 3,373,221 to May; U.S. Pat. No.3,377,406 to Newey; and U.S. Pat. No. 3,432,478 to May, all assigned toShell Oil Co.; U.S. Pat. No. 3,548,030 to Jernigan; and U.S. Pat. No.3,564,074 to Swisher et al., both assigned to Dow Chemical Co.; U.S.Pat. No. 3,634,542 to Dowd et al.; and U.S. Pat. No. 3,637,618 to May,both assigned to Shell Oil Co.

Preferably, the epoxy vinyl ester is prepared by reacting thepolyepoxide and the acid or derivative thereof in appropriate amounts,generally with heating and in the presence of a catalyst, such as atrivalent chromium salt, as for example CrC₃; or a phosphine; alkali,onium salt; or a tertiary amine, for example,tris(N,N-dimethylaminomethyl phenol). Optionally, the epoxy vinyl esterresin can be formed in the presence of a non-resinous, vinyl monomer,preferably not including styrene and preferably including vinyl toluene.The resulting product, which is a combination of the polymerizable vinylester and reactive diluent, will, in such an instance, constitute whatis referred to herein as a “vinyl ester resin” and more specifically asan “epoxy vinyl ester resin.”

Examples of epoxy compounds which may be used in such formationreactions include but are not limited to those found in bisphenolic typeepoxy resins, epoxy novolac type resins, amine type epoxy resins,copolymerized epoxy resins, multifunctional epoxy resins and the like.Preferably the epoxy used to form the present polymerizable vinyl esterhas about 2 to about 3 of an average number of epoxy groups in themolecule.

The bisphenolic type epoxy resin compounds which may be used include,but are not limited to, those found in bisphenol A, F and S type epoxyresins, each of such compounds preferably having 2 glycidyl groups inits molecule. Commercially available examples of bisphenol A type epoxyresin having 2 glycidyl groups in the molecule include those availablefrom Reichhold under the trade designation EPOTUF® 37-140. Commerciallyavailable examples of bisphenol F type epoxy resin having 2 glycidylgroups in the molecule include those available from Reichhold under thetrade designation EPOTUF® 37-138. In certain embodiments bisphenol Stype epoxy resin having 2 glycidyl groups in the molecule, andbrominated bisphenol A type epoxy resins, preferably also having 2glycidyl groups in the molecule, may also be used.

Epoxy novolac type resin compounds may also be used, and such resins areexemplified by phenolic novolac, cresolic novolac, aliphatic, alicyclicor monocyclic epoxy resins.

Aliphatic type epoxy resin compounds may also be used, and such resinsinclude, among others, hydrogenated bisphenol A type epoxy resin having2 glycidyl groups in its molecule. Such resins are commerciallyavailable from Reichhold under the trade designation EPOTUF® 37-051.

Alicyclic epoxy type resin compounds may also be used, and such resincompounds include, among others, alicyclic diepoxyacetal,dicyclopentadiene dioxide and vinylcyclohexene dioxide and the like,which have 2 epoxy groups in the molecule. Such epoxy resin compoundshaving one epoxy group in the molecule includes vinylhexene monoxide,glycidyl methacrylate and the like.

Monocyclic epoxy type resin compounds may also be used, and such resincompounds include, among others, resorcinol diglycidyl ether, diglycidylterephthalate and the like.

Amine type epoxy resin compounds may also be used, and such resincompounds include, among others, compounds having 4 glylcidyl groups inthe molecule.

These epoxy resins type compounds can be used alone or in combination.The average number of glycidyl groups in the molecule of the epoxy resinis preferably from about 1 to about 6, more preferably from about 2 toabout 4, and even more preferably from about 2 to about 3.

In preferred embodiments, the epoxy compound used to form thepolymerizable vinyl ester of the present invention corresponds toformula (II) below:

wherein

-   -   Ar is substituted or unsubstituted aryl.    -   R is substituted or unsubstituted divalent radical derived from        alkyl, oxyalkyl, arylalkyl, or oxyalkylaryl, alkyl or arylalkyl,    -   R¹ is independently H or R,    -   for each R_(x), x is independently 0 or 1,    -   for each O_(y), y is independently 0 or 1,    -   for each (O—R²)_(z), z is independently 0 to 4,    -   x, y and z is each independently 0 to 5 provided that x and y        can not both be zero, and n is from 1 to 5.

Examples of vinyl carboxylic acids and related compounds which may beused in the formation of the present polymerizable vinyl esters includebut are not limited to ethylenically unsaturated mono- and dicarboylicacids such as acrylic acid, methacrylic acid, itaconic acid, crotonicacid, cinnamic acid, fumanic acid, maleic acid, maleic anhydride and thelike, unsaturated (meth)acrylates such as methyl (meth)acrylate, ethyl(meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate,2-ethylhexyl (meth)acrylate, glycidyl (meth)acrylate, dodecyl(meth)acrylate and the like, nitriles such as (meth)acrylonitrile,amides such as (meth)acrylamide, N-methylol (meth)acrylamide, diacetone(meth)acrylamide, diethylaminoethyl (meth)acrylamide and the like. Forcertain embodiments, methacrylic acid is preferred. Examples of alcoholshaving an unsaturated group includes, among others, half-esters derivedfrom unsaturated dicarboxylic acids and/or unsaturated alcohols-such ashydroxyalkyl acrylates, for example, hydroxyethyl (meth)acrylate,hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate,pentaerythritol tri(meth)acrylate, glycerin di(meth)acrylate and thelike. Preferably, the acid or related unsaturated compound is one inwhich the reactive vinyl group is a terminal group.

Regarding the reactivity, flow performance and miscibility of thepolymerizable vinyl ester resin, it is generally preferred that thevinyl ester resins of the present invention have an ester number of fromabout 0 to about 25 mg KOH/g resin and which, when available in the formof a solution of 50 to 70% of reactive diluent monomer, have a viscosityof from about 50 to about 2000 mPa s at 23° C.

Generally, the polymerizable vinyl ester is present in the anchoringcomposition in the range of from about 20% to about 90% by weight of theentire adhesive composition, and even more preferably in an amount inthe range of about 20% to about 70%.

In preferred embodiments, the vinyl ester corresponds to formula IIIbelow:

wherein

-   -   Ar is substituted or unsubstituted aromatic radical with a        valence of at least two,    -   R is independently a substituted or unsubstituted divalent        radical derived from alkyl or arylalkyl,    -   R³ is a hydroxy substituted divalent radical derived from an        alkyl radical,    -   R⁴ is independently a vinyl carboxy radical or a epoxy radical,        provided that the ratio of n to the number of vinyl carboxy R⁴        groups is, on average for the composition, from about 0.4 to        about 2.0, and    -   n is from 1 to 5.

In highly preferred embodiments, the polymerizable vinyl estercorresponds to formula (IV) below:

where n is from 1 to about 5 and wherein the ratio of n to the terminalvinyl units is, on average for the composition, from about 0.4 to about2.0. A vinyl ester composition corresponding to formula (IV) isavailable from Reichhold under the trade designation Norpol Dion Ver9165 in a 65% by weight solution with vinyl toluene.

The Reactive Diluent

In general, it is contemplated that the teachings of the presentinvention can be used with great advantage in connection with any one ofthe large number of known reactive diluents, particularly reactivemonomers. Example of reactive diluents which may be use in connectionwith the broad teachings hereof include, among others, aliphatic vinylcompounds such as vinyl-, propene- and butene chloride, aromatic vinylcompounds such as styrene, vinyl toluene, divinyl benzene,p-t-butylstyrene and so on, diene compounds such as butadiene, isoprene,chloroprene, pentadiene and the like. Such reactive diluents can be usedalone or in combination. Nevertheless, the preferred aspects of thepresent invention contemplate the avoidance of styrene in thecomposition, and for this reason the preferred compositions do notcontain a substantial amount of styrene. In highly preferredembodiments, the reactive diluent comprises vinyl toluene, an preferablycomprises at least about 50% by weight of vinyl toluene, and even morepreferably at least about 70% by weight of vinyl toluene, with thebalance of the components making up the reactive diluent, if any, beingfree of any substantial amount of styrene.

While it is contemplated that the amount of reactive diluent relative tothe amount of polymerizable vinyl ester in the composition may varywidely depending on numerous factors particular to each application andcontemplated use, it is generally preferred that the vinylester:reactive diluent weight ratio is from about 0.8 to about 3, morepreferably from about 0.8 to about 1.5, and even more preferably fromabout 0.8 to about 1.3. Optionally but preferably the polymerizablevinyl ester is soluble in the reactive diluent.

Inhibitor

Inhibitors, and particularly free-radical inhibitors, are known to thoseskilled in the art. A preferred free-radical inhibitor is hydroquinone.Other suitable free-radical inhibitors include, but are not limited to,trimethylhydroquinone, hydroquinone monomethyl ether, t-butyl catecholand naphthaquinone. It is also contemplated that more than one freeradical inhibitor may be employed in the anchor composition. Thepolymerization inhibitor preferably comprises, more preferably comprisesin major proportion, and even more preferably consists essentially ofhydroquinone. Of course other inhibitor may be used alone or incombination with hyrdoquinone, such as for example, parabenzoquinone,methylhydroquinone, catechol and the like which are conventionallyemployed as polymerization inhibitors.

While it is contemplated that the amount of inhibitor in the compositionmay vary widely depending on numerous factors particular to eachapplication and contemplated use, it is generally preferred that theinhibitor is present in amounts of from about 0.005 wt % to about 5 wt%, and even more preferably from about 0.01 wt % to about 0.1 wt %.Optionally but preferably the polymerizable vinyl ester is soluble inreactive diluent.

Initiator

The vinyl ester resin composition of this invention can be easily curedby adding a curing catalyst, an initiator, or both. Representativeinitiators include aldehyde-amine condensation product, organic sulfonylchlorides, tertiary amines or mixtures thereof. For example, such acondensation product can be made from butyraldehyde and a primary amine,such an amine being, for example, aniline or butylamine. Also suitableas activators are tertiary amines such as N,N-dimethyl aniline,N,N-dimethyl toluidine, N,N-diethylaniline, N,N-diethyl toluidine,N,N-di-(2-hydroxy-ethy)-p-toluidine,N,N-bis(2-hydroxyethyl)-p-toluidine, N,N-bis(hydroxypropyl)-p-toluidineand the like. A preferred activator isN,N-di-(2-hydroxy-ethy)-p-toluidine. The curing catalysts includeorganic peroxides such as methylethylketone peroxides, t-butylperoxybenzoates, benzoyl peroxides, dicumyl peroxides and the like.

While it is contemplated that the amount of inhibitor in the compositionmay vary widely depending on numerous factors particular to eachapplication and contemplated use, it is generally preferred that theinhibitor is present in amounts of from about 0.005 wt % to about 5 wt%, and even more preferably from about 0.01 wt % to about 0.1 wt %.Optionally but preferably the polymerizable vinyl ester is soluble inreactive diluent.

Thixotroptic Agents

The present anchor composition may also comprise a thixotropic agent.The preferred hixotropic agent of the present invention causes thecomposition to become more fluid, i.e. less viscous, when agitated,stirred or mixed or otherwise subjected to such shear forces. It isuseful to include a thixotropic agent in the anchor composition toinsure that the composition has the desired viscosity during applicationand after the composition is applied. In addition, a thixotropic agentmay be added to an anchor composition to prevent the settling of othersolid components of the composition and to increase the viscosity of thecomposition. The thixotropic agent also facilitates dispensing of thecomposition because when a shear force is applied, e.g. expulsion of thecomposition from a dispensing gun, the thixotropic agent makes theresulting composition less viscous, and therefore, more easy to expelfrom the cartridges of the dispensing gun. The thixotropic agent may befound in the anchor composition in an amount in the range of from about0.5 wt % to about 10 wt %, and more preferably from about 1 wt % toabout 5 wt %. Typically, the use of thixotropic agent is not needed whenthe anchor composition is dispensed using a glass capsule. An example ofa suitable preferred thixotropic agent is fumed silica. Alsocontemplated are the various silicas made by the various methods knownin the art, including pyrolysis of silicon tetrachloride andprecipitation. Other suitable thixotropic agents include the variousorganoclays and various fibers. In some anchor compositions, thethixotropic agent may also be considered a filler. A suitable silicathixotropic agent is Aerosil® R202, which may be obtained from theDegussa Corporation of Ridgefield Park, N.J. It is also contemplatedthat more than one thixotropic agent may be used in the anchorcomposition

Fillers

The anchor composition of the present invention also preferablycomprises one or more fillers. Fillers are typically added tocompositions for various reasons, including to reduce shrinkage of thecomposition that may occur during polymerization and to reduce the costof the composition, as fillers replace a portion of the more expensivecomponents of the anchor composition. The filler may also provide forimproved bond strength of the anchor composition when polymerized andhelp to prevent the settling out of other particulate materials in thecomposition. Generally, the filler is an inert, inorganic, solid,particulate compound. By inert it is meant that the filler does notdetrimentally interact with any other component of the composition.Examples of suitable fillers include, but are not limited to, crushedglass, glass beads, quartz, silica, limestone, alumina, various clays,diatomaceous earth and other materials such as mica, flint powder,kryolite, alumina trihydrate, talc, sand, pyrophyllite, blanc fixe,granulated polymers such as polyethylene, hollow glass and polymerbeads, zinc oxide, novaculite, calcium sulfate and mixtures thereof.Preferred fillers are quartz, glass and silica. Fillers may be treatedwith coupling agents to improve bonding to the polymer matrix. Examplesof coupling agents, which may be used to treat the fillers, are silanes,titanates and zirconates.

Preferably, the present compositions contain fillers an amount of fromabout 10% to about 80% by weight of the composition, more preferablyfrom about 20 wt % to about 70 wt %, and even more preferably from about30 wt % to about 60 wt %.

The exact particle size of the filler will depend on the desiredconsistency of the composition and the method for dispensing the anchorcomposition. For example, fillers having a large average particle size(300 microns and larger) may clog static mixers that are used indispensing systems such as dispensing guns. On the other hand, fillershaving a large particle size can be used in glass capsules. Preferredparticle sizes are about 50 microns or larger. However, in cases where afiller is used to prevent the settling out of other particulate matterin a composition, a particle size smaller than 50 microns may bedesired. It is also recognized that a filler having a particle size lessthan 50 microns may be used in combination with other fillers, somehaving particle sizes greater than 50 microns.

Other Additives

The anchor composition may also contain a fragrance. A fragrance is usedin an anchoring composition to mask any odor of the composition that isthought undesirable or unpleasant. A preferred fragrance is AtlantaFragrance 16332. Similarly, a pigment may be employed to color theanchoring composition. Suitable pigments are known to those skilled inthe art.

Preferred Two Component Adhesives

In one embodiment of the present invention, the anchor composition isformed by mixing a first composition and a second composition. The firstcomposition contains the polymerizable vinyl ester compound andpreferably also at least a substantial amount, and preferablysubstantially all of the reactive diluent if present. The firstcomposition also preferably contains an inhibitor to inhibit curing ofthe adhesive until desired, and the second composition contains afree-radical catalyst. When the first composition and the secondcomposition are combined, polymerization occurs.

In a preferred embodiment, the first composition comprises vinyl esterand a filler. The first composition may also comprise a thixotropicagent, a chain transfer agent, a free-radical inhibitor, a fragrance, anactivator, a promoter and/or a pigment. The second compositionpreferably contains a free-radical catalyst. The second composition mayalso include filler, a thixotropic agent, a fragrance, and/or a pigment.It is also contemplated that both the first composition and the secondcomposition may contain some of the same components.

The weight ratio of the first composition to the second composition maybe in the range of 1 to 1 to about 40 to 1. Preferably, the weight ratioof the first composition (Part A) to the second composition (Part B) isabout 10 to 1.

EXAMPLES

The following examples are provided to illustrate particular embodimentsof the invention and are not intended to limit the scope of theinvention or the claims in any manner.

Experimental Protocols

Preparation of Two Part Anchor Compositions

The appropriate amounts of polymerizable vinyl ester resin are prepared.To the resin is added the appropriate amount of inhibitor, activator,fragrance and other ingredients. The composition is mixed, preferablyusing a dispenser. Next, the thixotropic agent is added with shearmixing followed by addition of the filler. If more than one filler is tobe included in the anchor composition, it is preferable to add the firstfiller, then mix, then add the second filler and so on until the desirednumber of fillers have been added to the composition until Part A of thecomposition is complete. The same general procedure as described aboveis used to make Part B consisting of catalyst thixotropic agent, filler,pigment and other ingredients.

The above preparation procedure is used for the examples, except for thecomparative example, in which case the adhesive was prepared inaccordance with the instructions provided.

Pull Out Performance

A medium weight concrete block approximately 4″×8″16″ substantially freeof surface moisture is used. Typically, five replicate pull out testsare run for each adhesive composition tested. First, three equallyspaced 110 mm deep holes approximately 14 mm wide are drilled in the8″×16″ side of the concrete block. Then, the holes are cleaned with abrush, with compressed air and a vacuum. An adhesive composition isinjected into the drilled holes, and a ¼″−20 threads per inch.×12 mmstainless steel rod type 304 is inserted into the adhesive-containinghole with a twisting motion. The time before pull out testing (alsocalled cure time) is in the range of about 0.5 hours to about 72 hours,as reported. The stainless steel rod was then connected to an Instronuniversal tester, Model TTC, Instron Corporation, Canton, Mass., and therods are pulled at 0.2″/minute until failure. The maximum load andfailure type was then recorded. Preferably, in an acceptable anchorcomposition, the pull out performance at one hour at a temperature of 30C is at least about 55 KN, at about 24 hour at a temperature of 30 C isat least about 65 KN, and after about 24 hours at about 80 C as measuredat a temperature of 80° C. is at least about 45 KN. Most preferably, thematerial that has been anchored to the concrete or masonry, or theconcert or masonry itself fails before the adhesive composition. As canbe seen from the following examples, the compositions of the presentinvention are capable of achieving pull out performance at one hour at atemperature of 23 C of at least about 75 KN (i.e., 80 KN), at about 24hours at a temperature of 23 C of at least about 90 KN (i.e., about 94KN), and after about 24 hours is measured at a temperature of 80° C. ofat least about 60 KN (i.e., about 62 KN).

Comparative Example

A leading commercially available anchor adhesive sold under the tradedesignation HY-150 by Hilti Aktiengesellschaft of Schaan, Liechtensteinis prepared and used in accordance with the instructions provided tomeasure various performance parameters as outlined in the aboveprotocols. The following results are observed:

Adhesive—HY-150

Pullout, 1 Hr. (KN)—53

Pullout, 24 Hr. (KN)—61.8

Pullout, 80° C. (KN)—41.6

Gel Time, min. (Trombomat)—9

Pumpability—good

Example 1

A two part adhesive composition having a Part A:Part B weight ratio of10:1 and the following formulations for Part A and Part B is preparedand used according to the above protocols:

PART A COMPONENT Wt. % in Part A Wt % in A + B pbwa Vinyl ester resin*33.08 30.07 69.29 Inhibitor (hydroquinone) 0.03 0.03 0.06 Initiator(Pergaquick A-150) 0.37 0.34 0.78 Thixotropic Agent 2.70 2.45 0 (AerosilR202) Filler (Sand) 54.52 49.56 0 Acrylate (SR-351) 9.31 8.46 19.5 *Thevinyl ester resin comprises about 35 wt % polymerizable vinyl estercompound(s) in accordance with the present invention and about 65 wt %of reactive monomer consisting of vinyl toluene.

PART B COMPONENT Wt. % in Part B Wt % in A + B pbwa Catalyst (Cadox 40E) 49.51 4.50 10.37 Thixotropic Agent 1.99 0.18 0 (Tixogel VZ) Filler(Sand) 47.52 4.32 0 Pigment (TiO2) 0.99 0.09 0

The various performance parameters as outlined in the above protocolsare measured for the adhesive composition and the following results areobserved:

Pullout, 1 Hr. (KN)—80.5

Pullout, 24 Hr. (KN)—94.5

Pullout, 80° C. (KN)—61.9

Gel Time, min. (Trombomat)—7

Pumpability—good

1. A curable adhesive composition for anchoring materials in or toconcrete or masonry comprising: a. vinyl ester resin comprising: i. fromabout 10 wt % to about 25 wt % of one or more polymerizable epoxy vinylester compounds; and ii. an ethylenically unsaturated monomer reactivewith said one or more polymerizable epoxy vinyl ester compounds; andfurther comprising: b. from about 5 wt % to about 10 wt % of reactivemultifunctional acrylate; c. curing catalyst; and d. activator; saidadhesive composition characterized in that it cures to provide a pullout performance after one hour at a temperature of 23° C. of at leastabout 70 KN.
 2. The adhesive composition of claim 1 wherein saidreactive multifunctional acrylate comprises acrylate that is at leasttri-functional.
 3. The adhesive composition of claim 1 wherein saidreactive multifunctional acrylate consists essentially of acrylate thatis at least tri-functional.
 4. The adhesive composition of claim 1wherein said reactive multifunctional acrylate comprises acrylate thatis at least tetra-functional.
 5. The adhesive composition of claim 1wherein said reactive multifunctional acrylate consists essentially ofacrylate that is at least tetra-functional.
 6. The adhesive compositionof claim 1 wherein said ethylenically unsaturated monomer comprisesvinyl toluene.
 7. The adhesive composition of claim 1 wherein the weightratio of vinyl ester to said ethylenically unsaturated monomer is fromabout 0.8 to about
 3. 8. The adhesive composition of claim 1characterized in that it cures to provide a pull out performance afterabout 24 hours at a temperature of 23° C. of at least about 80 KN. 9.The adhesive composition of claim 1 characterized in that it cures toprovide a pull out performance after about 24 hours at a temperature of80° C. of at least about 50 KN.
 10. A curable adhesive composition foranchoring materials in or to concrete or masonry comprising: a curableresin comprising a polymerizable polymer and an ethylenicallyunsaturated monomer reactive with said polymerizable polymer; andfurther comprising from about 5 pbwa to about 30 pbwa of reactivemultifunctional acrylate; curing catalyst; and activator, saidcomposition characterized in that it cures to provide a pull outperformance after about 24 hours at a temperature of 80° C. of at leastabout 50 KN.
 11. The adhesive composition of claim 10 wherein saidcurable resin is selected from the group consisting of acrylic resins,vinyl ester resins, urethane resins, polyester resins and combinationsof two or more of these.
 12. The adhesive composition of claim 10wherein said curable resin comprises polymerizable vinyl ester in amountof from about 10 wt % to about 25 wt % of the composition.
 13. Theadhesive composition of claim 12 wherein said reactive multifunctionalacrylate comprises a major proportion of acrylate that is at leasttri-functional.
 14. The adhesive composition of claim 13 wherein saidreactive multifunctional acrylate consists essentially of acrylate thatis at least tri-functional.
 15. The adhesive composition of claim 12wherein said reactive multifunctional acrylate comprises acrylate thatis at least tetra-functional.
 16. The adhesive composition of claim 15wherein said reactive multifunctional acrylate consists essentially ofacrylate that is at least tetra-functional.
 17. A curable adhesivecomposition for anchoring materials in or to concrete or masonrycomprising: a. vinyl ester resin comprising: i. from about 10 wt % toabout 25 wt % of one or more polymerizable epoxy vinyl ester compounds;and ii. an ethylenically unsaturated monomer reactive with said one ormore polymerizable epoxy vinyl ester compounds; and further comprising:b. from about 5 wt % to about 10 wt % of reactive multifunctionalacrylate, and further wherein said multifunctional acrylate comprises amajor proportion of acrylate that is at least tri-functional; c. curingcatalyst; and d. activator.
 18. The adhesive composition of claim 17wherein said reactive multifunctional acrylate consists essentially ofacrylate that is at least tri-functional.
 19. The adhesive compositionof claim 17 wherein said reactive multifunctional acrylate comprisesacrylate that is at least tetra-functional.
 20. The adhesive compositionof claim 17 wherein said reactive multifunctional acrylate consistsessentially of acrylate that is at least tetra-functional.
 21. Theadhesive composition of claim 1, wherein the ethylenically unsaturatedmonomer is selected from the group consisting of vinyl propene, butanechloride, styrene, vinyl toluene, divinyl benzene, p-t-butylstyrene,butadiene, isoprene, chloroprene, pentadiene and combinations thereof.22. The adhesive composition of claim 21, wherein the multifunctionalacrylate is selected from the group consisting of trimethylolpropanetriacrylate and dipentaerythritol tetraacrylate.
 23. The adhesivecomposition of claim 1, wherein the polymerizable epoxy vinyl estercompound is selected from the group consisting of bisphenolic type epoxyvinyl ester compounds, epoxy novolak type vinyl ester compounds, andamine type epoxy vinyl ester compounds, and further wherein themultifunctional acrylate is selected from the group consisting oftrimethylolpropane triacrylate and dipentaerythritol tetraacrylate. 24.The adhesive composition of claim 23, wherein the ethylenicallyunsaturated monomer is selected from the group consisting of vinylpropene, butane chloride, styrene, vinyl toluene, divinyl benzene,p-t-butylstyrene, butadiene, isoprene, chloroprene, pentadiene andcombinations thereof.